1. Field of the Invention
The present invention relates to list display apparatuses, list display methods, and list display programs. More particularly, the present invention relates to a list display apparatus, a list display method, and a list display program suitable to display multiple pieces of character string data in a list.
2. Description of the Related Art
Various display devices have hitherto processed characters and letters to be displayed according to Unicode in order to support character systems for the respective languages used over the world.
The characters and letters processed according to the Unicode include Arabic letters. Many of the Arabic letters vary their shapes in accordance with the positions at which the letters are arranged in words (at the beginning, at the end, or at intermediate positions) (refer to FIG. 10). In addition, when specific multiple letters are continuously used in a specific order, the series of multiple letters may be described as a ligature in which the multiple letters are joined to each other (refer to FIG. 11).
For Arabic letters having the above features, the letters before their shapes are varied illustrated in FIG. 10 and the multiple letters (single forms) on which the ligature is based illustrated in FIG. 11 are defined in U+06xx (x is a specific numeric character that is varied depending on the letter) in the Unicode. In contrast, the letters after their shapes are varied illustrated in FIG. 10 (the first letters, the intermediate letters, and the last letters) and the ligature illustrated in FIG. 11 are defined in U+FExx or U+FFxx.
As described above, for Arabic letters, the letters after their shapes are varied and the ligature are processed as the Unicode characters the numbers of which are separated from those of the letters of the single forms.
The various display devices have hitherto sorted the respective pieces of character string data in a certain sort order in order to display lists of the multiple pieces of character string data (for example, refer to Japanese Unexamined Patent Application Publication No. 3-210627).
In the sorting of English character string data, the character string data is often sorted in alphabetical order, and this sorting order coincides with the order in the Unicode. In the current navigation applications, letters with diacritical marks, such as umlaut, are processed as letters without diacritical marks for the sorting, as illustrated in FIG. 12.
Arabic letters are also often sorted in alphabetical order or according to the Unicode. In some devices, the letters after their shapes are varied illustrated in FIG. 10 are converted into the letters of the single forms for the sorting. For example, refer to Japanese Unexamined Patent Application Publication No. 2011-138281 and International Publication No. WO2008/018287.
However, since the ligature illustrated in FIG. 11 is processed as U+FExx in the Unicode for the ligature in the sorting, the ligature illustrated in FIG. 11 is sorted as a letter separate from the Arabic letters.
Accordingly, in the display of character string data for sorted Arabic letters in the list, it is difficult to find the character string data including the ligature from the list.